It does not appear that he was the author of any literary work, except a short treatise on the orthography of the Latin language, in which he attempted to settle various disputed points on this subject, by the authority of ancient inscriptions.[284] One of his contemporaries[285] attributes his literary silence to the fastidiousness of his taste, which led him to form in his own mind a standard of excellence, to which he despaired of attaining in the practice of Latin composition. Leonardo Aretino, in the irritation of his mind, occasioned by his unfortunate quarrel with Niccolo, ascribed his declining to appear in the republic of letters, in the character of an author, to his utter ignorance of the Latin language.[286] But this is undoubtedly one of those calumnies in which the scholars of that age indulged their spleen, without feeling the slightest compunction of conscience. To say nothing of the commendations of the literary acquirements of Niccolo, which occur in the writings of his learned contemporaries, his ample library may be regarded as an evidence of his scholarship. In modern times, the possession of an extensive and valuable collection of books is not of itself a certain proof of learning. But when it is considered that Niccolo had himself transcribed many of the volumes which adorned the shelves of his library, and that in the copies which he made of the Roman classics he divided the respective subjects into chapters, and prefixed to these divisions an abstract of their contents—what reason can there be to entertain doubts of his literary abilities? Several of the ancient writings recovered by Poggio abounded in errors, which Niccolo corrected in his transcripts; and he was accustomed to settle the text of the Latin authors by the comparison of various manuscripts. The execution of this task required considerable learning, and in its performance he appears in the venerable character of the parent of the useful art of verbal criticism.[287]